Dental handpiece

ABSTRACT

A dental handpiece having an improved novel tool-receiving sleeve arrangement facilitating the simplified actuation of an adapter sleeve of the handpiece, including rolling or rotatable members, preferably in the shape of spheres or balls, which effectively provide roller or ball bearing supports for the adapter sleeve so as to facilitate the threading movement of the adapter sleeve in an extraordinarily simple sequence.

United States Patent [191 Bareth [4 1 Sept. 2, 1975 DENTAL HANDPIECE[75] Inventor: Frich Bareth, Ummendorf, Germany [73] Assignee:Kaltenbach & Voigt, Biberach an der Riss, Germany [22] Filed: June 20,1973 [21] Appl. N0.: 371,845

[30] Foreign Application Priority Data July 12, 1972 Germany 2234321[52] US. Cl 32/26; 279/46 [51] Int. Cl. A61c 1/08 [58] Field of Search32/26; 279/46, 51

[56] References Cited UNITED STATES PATENTS 2,876,015 3/1959 Stever etal 32/26 X 3,400,459 9/1968 Stemler 32/26 3,475,817 11/1969 Loge 32/263,496,638 2/1970 Staunt.... 32/26 3,518,765 7/1970 Hayashi 32/263,530,586 9/1970 Weickenannt... 32/26 3,619,904 11/1971 Lundgren 32/263,631,597 1/1972 Lieb 32/26 3,775,851 12/1973 Flatland 32/26 PrimaryExaminer-Louis G. Mancene Assistant Examiner-J. Q. Lever Attorney,Agent, or Firm-Haseltine, Lake & Waters [5 7] ABSTRACT A dentalhandpiece having an improved novel toolr'eceiving sleeve arrangementfacilitating the simplified actuation of an adapter sleeve of thehandpiece, including rolling or rotatable members, preferably in theshape of spheres or balls, which effectively provide roller or ballbearing supports for the adapter sleeve so as to facilitate thethreading movement of the adapter sleeve in an extraordinarily simplesequence.

3 Claims, 1 Drawing Figure DENTAL HANDPIECE FIELD OF THE INVENTION Thepresent invention relates to a dental handpiece and, more particularly.to a novel arrangement enabling the simplified actuation of a tighteningor adapter sleeve for the handpiece.

DISCUSSION OF THE PRIOR ART Dental handpieces of this type are known,for example, from German Laid-open patent application No. 1,816,270, inwhich an adapter sleeve operatively engages a slide lock so as to movethe latter toward the tool-supporting end of the handpiece in adirection extending parallel to the axis of the handpiece. Thereby, theslide lock presses against an abutment which is contacted by a springretaining the adapter sleeve in alocking position, so as to remove thespring effect, permitting the adapter sleeve to move from its lockingposition, and facilitate withdrawal of the tool. In order to prevent thespring from reversely screwing the adapter sleeve, it is necessary toutilize a self-locking thread for the adapter sleeve. However,self-locking threads have only a relatively small pitch and, moreover,must be extremely precisely manufactured with close fits and tolerances.This has the result that the thread may be actuated only with extremedifficulty.

Accordingly, it is a primary object of the present invention to providea dental handpiece having an improved and novel arrangement facilitatingthe simplifled actuation of the adapter sleeve of the handpiece.

In order to achieve the foregoing object the present invention, in aninventive manner, provides rolling or rotatable members, preferably inthe shape of spheres or balls, which effectively provide roller or ballbearing supports for the adapter sleeve so as to facilitate thethreading movement of the adapter sleeve in an extraordinarily simplesequence. This is particularly advantageous since, in this manner, thespring force which operates in opposition to the threading processmovement through the use of the above-mentioned balls or rollers, doesnot restrictively occur to any significant extent.

In order to nevertheless provide with assurance the only weakly orpractically non-detected appearing selflocking, so as to prevent anyundesired unthreading of the adapter sleeve, the handpiece may be formedwith a releasable locking arrangement which is actuatable in theoperative end positions of the adapter sleeve. This locking arrangementmay advantageously be formed by a spring-loaded catch or lock, wherebyupon unthreading from the end-threaded position only the force of thelocking spring need be overcome. Furthermore, in order to assure thatthe rolling members are secured against falling out of grooves in whichthey are located, suitable limiting or arresting stops may be providedadjacent the passageways defined by the ball-receiving grooves.

BRIEF DESCRIPTION OF THE DRAWING Reference may now be had to a preferredexemplary embodiment of the invention taken in conjunction with theaccompanying drawing, in which the single FIG- URE illustrates in alongitudinal section a dental handpiece having an adapter sleeve shownin its locking position.

DETAILED DESCRIPTION Referring now in detail to the drawing, a forwardend sleeve of the handpiece is designated by the reference numeral 1.A'suitable gripping sleeve 2 is threaded into sleeve 1, with thethreaded portion between sleeves l and 2 being designated by referencenumeral 3.

A spindle sleeve 4 is located within sleeve 1, being supported at itsright-hand end as shown in the drawing within sleeve 1 by means ofa ballbearing 5. A further support for the spindle sleeve 4 is designated byreference numeral 6. At the right-hand end of the spindle sleeve 4 thereis provided a suitable connector or follower 7 for attachment thereto ofa drive shaft and motive means (not shown).

The spindle sleeve 4 is encompassed by a compression spring 8 whichcontacts an external ring-shaped projection 9 formed on the spindlesleeve comprising an abutment support and, which by means of a pressuremember 10 and a transversely extending pin 11, operates against anadapter sleeve 12 so as to bias the latter, as may be ascertained fromthe hereinhelow detailed description, into its locking position.

A dental tool 13 is inserted in the adapter sleeve I2. In the lockingposition, as illustrated in the drawing, the locking sleeve 12 lies withits outer conically-shaped tool-receiving end 15 of the spindle sleeve4, which is located in an axially fixed position within the handpieceor, in effect, in the sleeve 1.

For releasing the pressure of spring 8, an external adapter sleeve 16 ismounted on the handpiece so as to be rotatable with respect to an innersleeve I7 which is rigidly fastened to the handpiece. The inner wall ofthe adapter sleeve 16 and the outer wall of the inner sleeve 17 arerespectively provided with thread-like annular grooves 18 and 19, inwhich threading-engaging means is formed by means of spheres or balls 20extending into the grooves 18 and 19. A countersunk screw 21 extendsoutwardly of winding sleeve 16, having its shank portion located withina cooperative screw hole formed in a transmission sleeve 22, which in anunlocked position. is in an axial loaded engagement with the pressuremember 10, and is rotatable and axially displaceable together withsleeve 16.

For maintenance of the locking position of the sleeve 16 there isprovided a releasable locking arrangement. To this effect, thetransmission sleeve 22 includes in its outer wall a recessed portion 23,in which is located a locking ball 24. The locking ball rests within there cessed portion-23 under the operative effect ofa spring 25 which maybe, for example, a leaf spring. Upon the outward screwing or rotation ofthe adapter sleeve from its locking position, the force of spring 25 istraversed, and the ball 24 moves out of the recessed portion 23 androlls about the circumference of the transmission sleeve 22. A reverselydirected movement of ball 24 until engagement thereof in the recessedportion 23 occurs upon inward screwing into the locking position. I

Upon the outward screwing of the sleeve 16 from the illustrated lockingposition thereof, the countersunk screw 21 together with thetransmission sleeve 22 moves toward the left, whereby the last-mentionedsleeve exerts an operative force on the pressure member 10, and thelatter through the transversely extending pin 11 operates against thesleeve 12, and the latter is moved toward the left out of the spindlesleeve 4.

This causes, as may be ascertained, the force of the spring 8 to bereleased, so that in the outwardly pressed position of the sleeve 12,the tool gripping tongues thereof are opened so as to permit withdrawaltherefrom of the tool 13. In an analogous manner, upon the rotation ofthe sleeve 16 in the reverse direction. this will then form a lockingsequence. In order to assure that the rotatable members 20, which areformed as balls, are secured against dropping out, at both ends of thepassageways formed by the grooves 18 and 19, there are located suitablestopping elements 26 in the shape of bolts, which are secured to theinner sleeve 17.

While there has been shown what is considered to be the preferredembodiment of the invention, it will be obvious that modifications maybe made which come within the scope of the disclosure of thespecification.

What is claimed is:

l. A dental handpiece including a rotatable locking sleeve adapted todetachably support a dental tool; resilient spring means for biasingsaid locking sleeve into a locking position; a spindle sleeve withinsaid dental handpiece mounted in an axially fixed position with respectto said handpiece, said locking sleeve having a conically-shapedtool-receiving outer end, said spindle sleeve having a correspondinglyconically-shaped inner end at the tool-receiving end of said handpiececontacted by said conically-shaped end of said locking sleeve in thelocking position; an outer screwing-sleeve on said handpiece adapted tobe actuated for releasing the spring pressure on said locking sleeve,the improvement comprising; an inner sleeve fastened rigidly to saidhandpiece; screw-like annular grooves formed in respectively the innerperipheral surface of said screwing-sleeve and the outer peripheralsurface of said inner sleeve; said grooves being in axial alignment; androtatable means positioned in said grooves so as to form screw-likeinterengaging means between said screwingsleeve and said inner sleeve,said rotatable means comprising ball bearing rotatably supported in saidgrooves, said screwing-sleeve being actuatable between toolunlocking andtool-locking operative end positions; and comprising releasable lockmeans for locking said screwing-sleeve in at least one of said operativeend po sitions.

2. A dental handpiece including a rotatable locking sleeve adapted todetachably support a dental tool; resilient spring means for biasingsaid locking sleeve into a locking position; a spindle sleeve withinsaid dental handpiece mounted in an axially fixed position with respectto said handpiece, said locking sleeve having a comically-shapedtool-receiving outer end, said spindle sleeve having a correspondinglyconicallyshaped inner end at the tool-receiving end of said handpiececontacted by said conically-shaped end of said locking sleeve in thelocking position; an outer screwing-sleeve on said handpiece adapted tobe actuated for releasing the spring pressure on said locking sleeve,the improvement comprising; an inner sleeve fastened rigidly to saidhandpiece; screw-like annular grooves formed in respectively the innerperipheral surface of said screwing-sleeve and the outer peripheralsurface of said inner sleeve; said grooves being in axial alignment; androtatable means positioned in said grooves so as to form screw-likeinterengaging means between said screwingsleeve and said inner sleeve,said rotatable means comprising ball bearing rotatably supported in saidgrooves, said screwing-sleeve being actuatable between toolunlocking andtool-locking operative end positions; releasable lock means for lockingsaid screwing-sleeve in at least one of said operative end positions,said releasable lock means comprising an auxiliary sleeve having arecessed portion in its outer wall; a locking ball in said recessedportion; and spring means for holding said locking ball in said recessedportion.

3. A dental handpiece including a rotatable locking sleeve adapted todetachably support a dental tool; resilient spring means for biasingsaid locking sleeve into a locking position; a spindle sleeve withinsaid dental handpiece mounted in an axially fixed position with respectto said handpiece, said locking sleeve having a conically-shapedtool-receiving outer end, said spindle sleeve having a correspondinglyconically-shaped inner end at the tool-receiving end of said handpiececontacted by said conically-shaped end of said locking sleeve in thelocking position; an outer screwing-sleeve on said handpiece adapted tobe actuated for releasing the spring pressure on said locking sleeve,the improvement comprising; an inner sleeve fastened rigidly to saidhandpiece; screw-like annular grooves formed in respectively the innerperipheral surface of said screwing-sleeve and the outer peripheralsurface of said inner sleeve; said grooves being in axial alignment; androtatable means positioned in said grooves so as to form screw-likeinterengaging means between said screwingsleeve and said inner sleeve,said rotatable means comprising ball bearing rotatably supported in saidgrooves, said screwing-sleeve being actuatable between toolunlocking andtool-locking operative end positions; re-

leasable lock means for locking said screwing-sleeve in at least one ofsaid operative end positions; and stop means mounted at the axial endsof passageways defined by said grooves so as to prevent egress of saidro-

1. A dental handpiece including a rotatable locking sleeve adapted todetachably support a dental tool; resilient spring means for biasingsaid locking sleeve into a locking position; a spindle sleeve withinsaid dental handpiece mounted in an axially fixed position with respectto said handpiece, said locking sleeve having a conically-shapedtool-receiving outer end, said spindle sleeve having a correspondinglyconically-shaped inner end at the tool-receiving end of said handpiececontacted by said conically-shaped end of said locking sleeve in thelocking position; an outer screwing-sleeve on said handpiece adapted tobe actuated for releasing the spring pressure on said locking sleeve,the improvement comprising; an inner sleeve fastened rigidly to saidhandpiece; screw-like annular grooves formed in respectively the innerperipheral surface of said screwing-sleeve and the outer peripheralsurface of said inner sleeve; said grooves being in axial alignment; androtatable means positioned in said grooves so as to form screw-likeinterengaging means between said screwing-sleeve and said inner sleeve,said rotatable means comprising ball bearing rotatably supported in saidgrooves, said screwing-sleeve being actuatable between toolunlocking andtool-locking operative end positions; and comprising releasable lockmeans for locking said screwing-sleeve in at least one of said operativeend positions.
 2. A dental handpiece including a rotatable lockingsleeve adapted to detachably support a dental tool; resilient springmeans for biasing said locking sleeve into a locking position; a spindlesleeve within said dental handpiece mounted in an axially fixed positionwith respect to said handpiece, said locking sleeve having aconically-shaped tool-receiving outer end, said spindle sleeve having acorrespondingly conically-shaped inner end at the tool-receiving end ofsaid handpiece contacted by said conically-shaped end of said lockingsleeve in the locking position; an outer screwing-sleeve on saidhandpiece adapted to be actuated for releasing the spring pressure onsaid locking sleeve, the improvement comprising; an inner sleevefastened rigidly to said handpiece; screw-like annular grooves formed inrespectively the inner peripheral surface of said screwing-sleeve andthe outer peripheral surface of said inner sleeve; said grooves being inaxial alignment; and rotatable means positioned in said grooves so as toform screw-like interengaging means between said screwing-sleeve andsaid inner sleeve, said rotatable means comprising ball bearingrotatably supported in said grooves, said screwing-sleeve beingactuatable between tool-unlocking and tool-locking operative endpositions; releasable lock means for locking said screwing-sleeve in atleast one of said operative end positions, said releasable lock meanscomprising an auxiliary sleeve having a recessed portion in its outerwall; a locking ball in said recessed portion; and spring means forholding said locking ball in said recessed portion.
 3. A dentalhandpiece including a rotatable locking sleeve adapted to detachablysupport a dental tool; resilient spring means for biasing said lockingsleeve into a locking position; a spindle sleeve within said dentalhandpiece mounted in an axially fixed position with respect to saidhandpiece, said locking sleeve having a conically-shaped tool-receivingouter end, said spindle sleeve having a correspondingly conically-shapedinner end at the tool-receiving end of said handpiece contacted by saidconically-shaped end of said locking sleeve in the locking position; anouter screwing-sleeve on said handpiece adapted to be actuated forreleasing the spring pressure on said locking sleeve, the improvementcomprising; an inner sleeve fastened rigidly to said handpiece;screw-like annular grooves formed in respectively the inner peripheralsurface of said screwing-sleeve and the outer peripheral surface of saidinner sleeve; said grooves being in axial alignment; and rotatable meanspositioned in said grooves so as to form screw-like interengaging meansbetween said screwing-sleeve and said inner sleeve, said rotatable meanscomprising ball bearing rotatably supported in said grooves, saidscrewing-sleeve being actuatable between tool-unlocking and tool-lockingoperative end positions; releasable lock means for locking saidscrewing-sleeve in at least one of said operative end positions; andstop means mounted at the axial ends of passageways defined by saidgrooves so as to prevent egress of said rotatable means from saidgrooves.